THE SKTX AXD TTS APPF^XDAnKS 



391 



cork. Sections are cut transversely to the ridges, stained with haematoxylin-picro- 

 acid-fuchsin (technic3, p. 21), and mounted in balsam. Thick sections should be 

 cut for the study of the coil glands with their ducts; thin sections for cellular 

 details of the layers. 



(2) Prepare in the same manner and for contrast with the preceding, sec- 

 tions of thin skin from almost any part of the body. 



(3) Prepare a piece of negro skin in the same manner and note the position of 

 the pigment. 



The Nails 



The nails are modilicd epidermis. Each nail consists of: (a) a 

 body, the attached uncovered portion of the nail; (b) a, free edge, the 

 anterior unattached extension of the body; (c) the nail root, the pos- 

 terior part of the nail which lies under the skin (Fig. 275). 





'\^-^--^ 



Fig. 275. — ^Longitudinal Section through Root of Human Nail and Nail Bed. X 10. 

 (Schaper.) a, Body of nail; h, free edge; c, root of nail; d, epidermis; e, eponjxhium; 

 f, stratum germinativum of nail; g, folds in derma of nail bed; //, bone of finger; k , 

 hyponychium. 



The nail lies upon a specially modified portion of the corium, the 

 nail bed, which beneath the nail root and somewhat forward of the 

 root is known as the matrix. The nail bed is bounded on either side 

 by folds of skin, the nail wall, while between the nail wall and the 

 nail bed is a furrow, the nail groove (Fig. 276). 



The nail bed consists of corium. Its connective-tissue fibres are 

 arranged partly horizontal to the long axis of the nail, partly in a 



